Drain plug mystery

[purple_duckk]

I would like to start off by calling myself a bone head. So I bought a house with an inground pool having never owned a pool before. Well, I opened it last weekend unplugging the skimmers and filling with water and chlorinating the Crud out of it. It has gone from green to cloudy blue/white and I am waiting for my TF100 kit. It occurs to me today at work that I never pulled the main drain plug so I get in and swim to the bottom, feel around and sure enough there is a plug there. 2 problems: 1 I can't see the plug to get a good idea how to remove it and 2 being 9.5 feet down means I have about 10 seconds of air in my lungs to work with it after I get down to the bottim and find it by feel. It feels like a standard rubber plug that loosens after you unscrew it but there is no wing nut, just a long hex head bolt coming out the top. I have scoured the site looking for pictures of main drain plugs, but to no avail. Any suggestions for my stupid butt?

 

[waste]

Welcome to TFP!!

How can you possibly think you're stupid for not knowing what to do with something you've never had to do before :?:

For now I'd leave any plug in the MD alone It probably wasn't plugged on winterizing and any plugs that are in there are there to keep the water in the pool :!:

I'll assume you have at least 2 lines coming into the pump with valves on them - can you draw water through either valve at will? If so, the line is already open and able to supply water to the pump. 8)

Let us know a little more about your filter system plumbing and we'll help you figurer out whether or not to play with any plugs in the MD

 

[purple_duckk]

The plumbing is obviously quite old. I believe the pool was built in the 60'sI am pretty sure the system has only 1 line coming in and it certainly can't pull from the lines independantly since there is only 1 valve and the filter doesn't have a multi-valve, but check out my pics and see if you can decipher what's going on there. The reason I'd like to pul the main plug is to increas my circulation so I can get all of the dirt on the bottom of the pool moving to the filters. If I am only relying on the skimmers I don't think I will ever get my water clear. There seems to be a lot of sediment on the bottom, especially the deep end.

 

[dmanb2b]

ok...that looks old...but I'm no plumbing expert....you could also hook up your vacum and weigh it down and let it sit in the deep-end...just throwing out some ideas for you...this will help suction water from your pool bottom until you figure out the main drain issue

 

[JasonLion]

You should be able to vacuum up the stuff on the bottom. I would do that soon, while you continue to puzzle out the main drain. You can point one of your returns down towards the deep end to improve circulation.

Keep in mind that the main drain might leak, or be blocked. With plumbing that old it is probably at least as likely that the main drain doesn't work as that it does. If you do get the plug out, be prepared to put it back in again if you start losing water.

 

[waste]

Thanks for the pics They help us head in the right direction to see if you have an operable MD

Now the first (at least) set of follow up questions:

1) What happens when you open or close the valve? (Does one of the skimmers open or shut off, do you start drawing air into the pump...)

2) Does the deep end skimmer have 2 open ports in it? (possibilities if "yes" - too many to ask right now)

3) Any idea as to what the clamp secures on the non-valved pipe (I also see a similar one on the return line)? (I strongly doubt that this pertains to your MD, but ... 'Inquiring minds want to know' )



You do have 2 lines coming into the pump - they have to join before entering the 1 port on the pump What I'm looking to find out is what these lines coming into the pump do :-D

* * * * *
Jason answered while I was and saved me a bunch of keystrokes 8)

 

[JasonLion]

3) Any idea as to what the clamp secures on the non-valved pipe (I also see a similar one on the return line)? (I strongly doubt that this pertains to your MD, but ... 'Inquiring minds want to know' )

I am fairly sure those are taps into the pipe that used to be used to hook up a tablet chlorinator. If the chlorinator was removed and the taps were plugged they could look just like that.

 

[purple_duckk]

Ok, I'll get a vac head and hose tomorrow. Do I need one of those vac plates for my skimmer since it has a hose sized hole at the bottom? Would either of you guys have pics of a typical main drain winter plug vs a perm main drain plug?

Waste, after seeing your post on the number of inputs I reassessed my plumbing. You are right it does have two inputs. I was thinking they were the return lines, I'll get to why I thought that in a sec.
Answer 1) When I shut the one off the pump continues to pull water, but both skimmers shut down. The weird thing is when I dove down to the main drain earlier today I did it while the pump was running and I didn't feel any suction there. Is it possible there is a 4th water draw point? Also when I close the valve the filter pressure drops about 3 PSI to 7 and when I open it it jumps back to 10.

Answer 2) What do you mean by 2 open ports? It has one hose sized hole in the bottom just like the shallow end one but there is a smaller PVC circle about 1 foot behind it that is completely filled with dirt. I'll add pics.

Answer 3) they are 1/2" threaded ports, I think for the Polaris robot(280 I think) as there is a booster I don't have pictured but I do have. this is why I thought the 2nd input was a return. I thought it was a second input pipe to add the more pressurized water from the booster to drive the Polaris. Now knowing the correct flow, I can't imagine how the booster hooks in. Any help in that area would be great.

I have a newer Tagelus TA60 top mounted valve sand filter with a multi-position valve I haven't installed yet. Is there some special way I should plumb this up so it takes advantage of the 2 inputs?

 

[launboy]

I have a newer Tagelus TA60 top mounted valve sand filter with a multi-position valve I haven't installed yet. Is there some special way I should plumb this up so it takes advantage of the 2 inputs?

No special way needed to plumb it. Just to be clear, the two suction lines are where the pump sucks water from the pool. The water then flows out the top of the pump into the filter. You should plumb the inlet and outlet on the new filter the same as the old one. Then the water flows out of the filter, and back through (what looks like) a single pipe. If you want to add a Polaris that needs a booster pump, you'll need to add another pipe going back to the pool for the return coming out of the Booster Pump.

Several comments, in this post and others, discussing something no one should try, were removed at the request of the original poster. JasonLion

HTH,
Adam

 

[purple_duckk]

I have a Spare Air lined up to use to stay at the bottom for a few minutes at a time safely. Now I just need to figure out the nature of the plug and vac the bottom so the water clears up enough to get a good look at it.

 

[Gooserider]

In our gunnite pool, which is also on the older side, the skimmer has two holes in the bottom, one hole goes to the pump, the other is connected to the main drain.

At the main drain, there are also two ports - one port goes to the skimmer basket, the other is "plugged" with a pop-off valve that "should" stay closed at all times - it only functions if you drain the pool or otherwise manage to have the ground water level higher than the pool water level, in which case it opens to allow the ground water to partly fill the pool, and prevent the pool from getting popped out of the ground by flotation...

The pop-off valve should NOT be removed unless you need to replace it - they go bad after 20 years or so, and will start to leak - a place to check if you start loosing water and can't find any other obvious leaks...

One other issue - you mention having a "Spare Air" - not sure what that is, but it sounds like a surface use item such as a firefighter might use - these are NOT suitable for use underwater, as the regulator isn't designed for such an application.

You should use a SCUBA setup, and then only if you have had at least some basic training in how to do so - SCUBA gear is quite safe if properly used, but if not used properly, you can kill yourself in as little as THREE FEET of water... Be careful / Be Safe...

Gooserider

 

[purple_duckk]

Goose,

I appreciate your insight. It is possible I have the pop off valve you are talking about. Being in Detroit means a pretty high water table so that kind of makes sence.

I AM losing water, but it didn't start right away and it seems to have held water all fall, winter and summer until I opened and filled it. I have shut off the skimmers(thanks to Waste I found out what that valve on my pipes is for) and am pulling water from a source unknown to me as the plugged main drain didn't seem to be pulling vaccum when I dove down to see if there was a plug in it yesterday.

As for the Spare Air it is a scuba secondary air system that holds 20 or so breaths of air at 10 feet. Gramps was a master diver and he took me diving, I just don't have my cert or any equipment of my own. My boss is letting me borrow his spare air and his tank to refill it off of. I'm hoping to only need one trip to the bottom after I vac the water to clear it up and I figure out exactly what I am dealing with. I fully intend to not die at the bottom of my first pool! hahaha

 

[Gooserider]

Goose,

I appreciate your insight. It is possible I have the pop off valve you are talking about. Being in Detroit means a pretty high water table so that kind of makes sence.

I AM losing water, but it didn't start right away and it seems to have held water all fall, winter and summer until I opened and filled it. I have shut off the skimmers(thanks to Waste I found out what that valve on my pipes is for) and am pulling water from a source unknown to me as the plugged main drain didn't seem to be pulling vaccum when I dove down to see if there was a plug in it yesterday.

As for the Spare Air it is a scuba secondary air system that holds 20 or so breaths of air at 10 feet. Gramps was a master diver and he took me diving, I just don't have my cert or any equipment of my own. My boss is letting me borrow his spare air and his tank to refill it off of. I'm hoping to only need one trip to the bottom after I vac the water to clear it up and I figure out exactly what I am dealing with. I fully intend to not die at the bottom of my first pool! hahaha

Sounds reasonable - if you have diving experience, I'm sure you can understand why I was concerned... I have a PADI cert from back in my college days, but probably only about 10-15 hours total down time, so I'm no expert, but am aware of the hazards...

As to the main drain setup, I don't know if that is what you have, but it seems like a possibility that I hadn't seen mentioned... You mentioned that you started loosing water after you filled the pool - any chance that the reason you hadn't been before filling is that the level in the pool was about the same as the local water table? That would match the symptom of a leaky pop-off - until there was a height difference to create a pressure head on the pool water, there wouldn't have been any pressure to drive water through the popoff, so no leakage. Once you filled the pool the pressure difference would push water backwards through the popoff to try and restore the balance. When we had the bad valve on our pool, it was a very slow leak, on the order of two-three inches extra loss a week beyond evaporation.

Gooserider

 

[sbluhm]

Goose,

I have shut off the skimmers(thanks to Waste I found out what that valve on my pipes is for) and am pulling water from a source unknown to me as the plugged main drain didn't seem to be pulling vaccum when I dove down to see if there was a plug in it yesterday.

If there are two pipes coming in to the pump, but only one has the shutoff valve, the water must be coming from the other pipe. Usually the second pipe is the second skimmer or the main drain, although you say you lose suction at both skimmers. If it's not a main drain or the 2nd skimmer, my guess is that there is a below the water-line inlet somewhere along the side of the pool which is sucking in water in addition to the skimmer. Do you see an inlet like that anywhere around the pool?

 

[purple_duckk]

Ok, so I have a ton more info today. I got a vac head and some vac hose and cleared out a ton of stuff. so much so that I drove my filter pressure to 26 instead of the usual 10 by vacing some Crud out of the deep end. Backwashed and kept vacing as much as I could. Dove down with a mask and was able to look at the drain and I was wrong. The drain is a 4 inch pvc pipe with the center being plugged with what looks like a standard rubber plug and 90 degrees off of that tucked up under the PVC lip is a tube maybe 1.5" that is sucking water like crazy. When I tunred off the skimmers and dove down it was sucking a lot more but when I had the skimmers on too it was still sucking water, just not the crazy amounts when it was running by itself. Do I need to put the copper diverter over the hole or should I leave it open?

Goose, It is possible it was at the local water table, but both of my neighboors have finished basements and the pool was down about 20-24 inches below ground level when it was holding water. The only things above this are the skimmers and the return lines so I am imagining the leak has to be one of those places. Also I didn't notice the fast water loss until about 2-3 days after I filled the pool and turned on the filters. Here are the numbers and actions I have done to test where the leak is: Skimmers and main drain running from 11 PM to 7 am lose 3/4 of an inch or about 250 gallons Close the skimmers valve, run from 7:30 AM to 3:30 PM on a very cloudy humid 70 degree day lose 2 inches or 660 gallons of water. Now I am going to turn off the pumps and plug the skimmers and wait 12 hours.

 

[Gooserider]

Theory says that it is best to have some circulation both from the main drain and from the surface skimmers, as that will give the best water mixing and regular turnovers.

What it sounds like is that the opening you said was plugged is where the popoff should be, and the other pipe is the main drain connection.

Leak tracing can be a challenge for sure, sounds like you are starting to go about it the right way... Another technique that is a bit more effort is to attempt to plug all the lines and pressurise them, see if they hold pressure - if they do the problem is in the pool, if not you need to start taking apart plumbing until you find the leaky section...

One place to look for leaks is where the plumbing fittings come through the pool walls, both inlet and outlet - if need be take out the eyball fittings so you can see the area. There is supposed to be a sealant between the concrete and the pipes, but over time this can break down - they make underwater hardening epoxies that can be mixed up and pushed into any gaps there, and seem like they make a pretty durable seal. The stuff I used was in two cardboard tubes - you cut equal lengths off each tube and mixed them together until you had a uniform color, then pushed it into any cracks, etc. Was supposed to be designed to bond to both concrete and PVC.

Gooserider

 

[waste]

I'd have to say that your MD is indeed working

Your leak is certainly strange... by rights it shouldn't matter about the suction side while the pump is running. A suction side leak 'should' draw air into the system when the pump is running and therefore not leak - a return side leak would be less when the pump is off and exasperated by having the extra force of flowing water. If the leak in one of the skimmer lines ( or the line they share) was large enough to allow some water out while still sucking air (or overcome the vacuum), it'd have to be an impressive leak Please read the Leak Detection article in Pool School for some tips on this.

**A quick thanks to Jason on the taps in the lines -- if I can find the time and remember to make the post- I'll get into why the suction side tap is IMHO very wrong and ask for more knowledgeable opinions.**

Duckk, please keep us informed as to your progress

 

[purple_duckk]

Waste and everyone else, thanks for all of the great advice! You guys have saved me so much time and money and I have only been here for a few days!

I was pretty excited about the MD being in good shape. I was worried I might have done some damage by not unplugging it while opening the pool. Should I put in the old copper diverter over the hole or leave it open? No kids, just me so no real worry of getting stuck to the bottom.

Looks like my leak problems go like this: Main drain only is the worst with 660 gallons over 8 hours. Main drain with both skimmers running is the next with 250 gallons over 8 hours. And 1.5 hours to go with skimmers plugged not running the pumps but so far it hasn't lost any, so at least the pool itself seems to be holding water. Would you recommend diving down and plugging the MD and running it with just skimmers to see how much it loses? Also I was thinking of plugging each skimmer individually with the MD open.

Are there any other steps you might recommend to track this bad boy down? I read the leak detection right off the bat but I have no visable leaks and no real air issues.

As I am going to put in my new Tag filter soon should I redo as much of those lines as I can and get rid of those taps? Also how hard would it be to redo the pipes to be able to use the booster I have so I can run my Polaris?

 

[purple_duckk]

Ok, I plugged the deep end skimmer and ran the pumps for 7 hours last night with no water loss, however there was a significant amount of air in my pump pot the whole time and every so often the returns would start to bubble like a hot tub. So this morning I plugged the shallow end skimmer and the pot cleared of all the air and the lines stopped bubbling. I haven't yet run it long enough to know how much water is lost over how much time.

 

[sbluhm]

Also how hard would it be to redo the pipes to be able to use the booster I have so I can run my Polaris?

The Polaris 280 usually has a dedicated return line to the pool where it plugs in. From your pictures, it doesn't look like there is a second return line to the pool? I know the Polaris instructions say to use a dedicated return, if you don't have one are you planning to send the booster output through the existing return? Maybe some of the experts can advise if this will work or not?